Recently, in radio communication, more particularly, in mobile communication, various information such as images and data, in addition to sound, have been an object of transmission. It is expected that necessity of high-speed transmission will further increase in the future, and therefore a radio transmission technology is required that realizes high transmission efficiency using limited frequency resources efficiently in order to perform high-speed transmission.
As one of such radio transmission technologies, OFDM (Orthogonal Frequency Division Multiplexing) can be cited (for example, see Non-patent document 1). It is known that the OFDM has a high frequency usage efficiency, a low interference between symbols under a multipath environment, and so on, and is effective for improving transmission efficiency.
Non-patent Document 1: WS No. 197, “OFDM modulation technology for digital broadcast/mobile communication,” published by triceps Corporation, on Mar. 7, 2000.